Gov. Arnold Schwarzenegger of California has proposed phasing out the state’s main student-aid program, a move that would eliminate grants for more than 100,000 students each year and would mark a historic downgrading in the affordability of California’s colleges and universities.

The proposal, announced on Thursday, would close the Cal Grant program, one of the country’s most generous state-run student-aid programs, to help California deal with a $24-billion budget deficit. The governor’s aides proposed the cutback at a budget hearing after saying that their previous plan — to borrow $5.5-billion — had been shortsighted.

Under the new plan, students who have Cal Grants would keep them until they graduated, but no new grants would be issued, saving an estimated $180-million immediately and more than $900-million as the program was phased out, according to the Los Angeles Times. The governor’s proposal is tentative and could be changed as lawmakers adopt a budget.

Student-aid advocates in California were at a loss for words to describe the potential effect of losing the student-aid program, which was started in 1956.

“It’s devastating, it’s stunning, it’s mind-boggling the impact that this would have,” said Edie Irons, a spokeswoman for the Institute for College Access & Success. “It’s hundreds of thousands of students that would be affected, and it would just ripple across the state.”

Nearly 300,000 students receive some form of Cal Grant support. The size of the grant awards varies by institution. In 2007 the average award was $8,746 at private colleges in the state, $3,813 at the University of California, $2,090 at California State University, and $1,551 at the state’s community colleges, according to an analysis by the institute. —Josh Keller